Will allow you to display descriptions in the Wordpress Theme Customisation API settings sections.

functions.php

add_action('customize_controls_print_footer_scripts', function() {

  ?>
  <script type="text/javascript">

    (function($, window) {

        $(document).ready(function() {
            var $customisationOptions = $("#customize-theme-controls");

            if ($customisationOptions.length) {

                $(".control-section", $customisationOptions).each(function() {
                    var $this           = $(this);
                    var $heading        = $(".customize-section-title", $this);
                    var $headingTitle   = $heading.attr('title');
                    var $sectionContent = $(".customize-section-content", $this);

                    if ($headingTitle) {
                        $heading.removeAttr('title');
                        $sectionContent.append('<li class="customise-control"><p>'+$headingTitle+'</p></li>');
                    }
                });

            }
        });

    })(jQuery, window); 

  </script>
  <?php

}, 999);